      [:button.btn.btn-primary {:aria-label "Search"}
       [:i.fa.fa-search {:aria-hidden true}]]]]])
 
+(defn ^:private maybe-deref
+  "(deref x), unless it's nil."
+  [x]
+  (when (some? x) @x))
+
 (defn nav
   "App navigation bar."
   []

            [desdemona.ui.dom :as d]))

(secretary/defroute "/" []
  (session/put! :current-page dashboard-component))

(secretary/defroute "/table" []
  (session/put! :current-page table-component))

(defn ^:private search-form-component
  []

   [:div.container-fluid
    [:nav
     (let [current-page (session/get :current-page)
           active? #(= (maybe-deref current-page) %)]
       [:ul.nav.nav-tabs
        [:li {:class (when (active? dashboard-component) "active")}
         [:a {:href "/"} "Dashboard"]]
